Optimal Design of Open Channel Section Incorporating Critical Flow Condition
Publication: Journal of Irrigation and Drainage Engineering
Volume 132, Issue 5
Abstract
The flow at critical condition of an open channel is unstable. At critical condition, a small change in specific energy will cause abrupt fluctuation in water depth of the channel. This is because the specific energy curve is almost vertical at critical state. Therefore, if the design depth of the channel is near or equal to critical depth of the channel, the shape of the channel must be altered to avoid a large fluctuation in water depth. In the present study, a nonlinear optimization model is presented for designing an optimal channel section incorporating the critical flow condition of the channel. The optimization model derives the optimal channel section at a desirable difference from the critical condition of the channel so that a small change in the specific energy of the channel will not cause an abrupt change in flow depth. The objective of the optimization model is to minimize the total construction costs of the channel. Manning’s equation is used to specify the uniform flow condition in the channel. The developed optimization model is solved by sequential quadratic programming using MATLAB. Applicability of the model is demonstrated for a trapezoidal channel section with composite roughness. However, it also can be extended to other shapes of channel.
Get full access to this article
View all available purchase options and get full access to this article.
References
Babaeyan-Koopaei, K., Valentine, E. M., and Swailes, D. C. (2000). “Optimal design of parabolic-bottomed triangle canals.” J. Irrig. Drain. Eng., 126(6), 408–411.
Chanson, H., and Montes, J. S. (1995). “Characteristics of undular hydraulic jump: Experimental apparatus and flow patterns.” J. Hydraul. Eng., 121(2), 129–144.
Chow, V. T. (1959). Open channel hydraulics, McGraw-Hill, New York.
Das, A. (2000). “Optimal channel cross section with composite roughness.” J. Irrig. Drain. Eng., 126(1), 68–72.
Froehlich, D. C. (1994). “Width and depth constrained best trapezoidal section.” J. Irrig. Drain. Eng., 120(4), 828–835.
Guo, C., and Hughes, W. C. (1984). “Optimal channel cross section with freeboard.” J. Irrig. Drain. Eng., 110(3), 304–314.
Horton, R. E. (1933). “Separate roughness coefficients for channel bottom and sides.” Eng. News-Rec., 111(22), 652–653.
Jain, A., Bhattacharjya, R. K., and Srinivasulu, S. (2004). “Optimal design of composite channels using genetic algorithm.” J. Irrig. Drain. Eng., 130(4), 286–295.
Loganathan, G. V. (1991). “Optimal design of parabolic canals.” J. Irrig. Drain. Eng., 117(5), 716–735.
Mironenko, P. A., Willardson, L. S., and Jenab, S. A. (1984). “Parabolic canal design and analysis.” J. Irrig. Drain. Eng., 110(2), 241–246.
Monadjemi, P. (1994). “General formation of best hydraulic channel section.” J. Irrig. Drain. Eng., 120(1), 27–35.
Ohtsu, I., Yasuda, Y., and Gotoh, H. (2003). “Flow condition of undular hydraulic jump in horizontal rectangular channels.” J. Hydraul. Eng., 129(10), 948–955.
Swamee, P. K., Mishra, G. C., and Chahar, B. R. (2000). “Design of minimum seepage loss canal sections.” J. Irrig. Drain. Eng., 126(1), 28–32.
Information & Authors
Information
Published In
Copyright
© 2006 ASCE.
History
Received: Nov 9, 2004
Accepted: Sep 30, 2005
Published online: Oct 1, 2006
Published in print: Oct 2006
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.